Whistle Moan Hum or Whine Type Noise with A/C Compressor On - keywords hum HVAC line rear thump
| Subject: | Whistle Moan Hum or Whine Type Noise with A/C Compressor On |
| Models: | 2004-2006 Cadillac Escalade ESV |
| 2004-2006 Chevrolet Suburban |
| 2004-2006 GMC Yukon XL, Yukon XL Denali |
This PI has been revised to include the 2006 Model Year. Please discard PIT3638.
The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.
Condition/Concern:
Some owners may comment of a whistle, moan, hum, whine or thumping type noise with the rear of the vehicle with the A/C on. The noise may be difficult to duplicate and can only occur when the A/C compressor is on. In most cases the noise will occur during a deceleration.
Recommendation/Instructions:
This noise may be caused by the rear Thermal Expansion Valve (TXV). Currently, the only repair would be to replace the TXV valve.
Please follow this diagnostic or repair process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed.
